The Safe Drinking Water Act (SDWA) is the federal law that protects public drinking water supplies throughout the nation. Under the SDWA, the US EPA sets standards for particular contaminants in drinking water. Water supply systems must test for these contaminants and, if necessary, the water is treated to reduce contaminants to the maximum contaminant levels (MCLs) set for each contaminant.

Each year water supply systems test these water quality parameters, at different intervals, established by the Illinois EPA and US EPA to protect public health. Along with every public water supply in the United States, the City of Highland Park publishes an annual report, the Consumer Confidence Report (CCR). Read the current CCR here.

The annual CCR only details the detected results of water quality monitoring over the previous year. Any contaminant that was not detected is not added to the CCR but is submitted to the Illinois EPA. All water quality monitoring results can be found on the IEPA's Drinking Water Watch website. Any contaminant that the City of Highland Park tested for, and those results, can be found there.

Below is a list of contaminants that The City of Highland Park monitors for and the frequency at which it is done. To read previous CCRs please visit our archived CCRs here.Continuously monitored (at multiple locations):

Chlorine Residual on Finished Water – guard against microbial contamination between the plant and the consumer

Turbidity on Finished Water – measurement of clarity, a key measurement of treatment performance

ORP (common measurement for water quality) on Raw Water – detects any changes needed in the dosing of disinfectant

Tested Daily:

Coliform on Raw Water – to see microbial contamination of water that will be treated

Coliform on Finished Water – to verify treated water bacteriological quality

pH & Temperature on Raw Water - to optimize treatment chemical dosing

Turbidity on Raw Water – performed every 4 hours to measure clarity of water that will be treated

pH on Finished Water – verifies water quality

Chlorine Residual and Turbidity on Finished Water – performed every 4 hours to verify water quality

Lead and Copper Rule - 30 Lead and Copper samples collected throughout the City’s water distribution system to verify optimal corrosion control treatment. For more information on lead please visit our lead information page.